[Resuscitation after intoxication with amitriptylin]

Intoxications with tricyclic antidepressants are often life threatening situations. In consequence of interference with many organ systems specific treatment consists in transportation to hospital under cardiopulmonary monitoring by physicians. The multiple possibilities of complications require the following treatments: continuous monitoring of the cardiovascular system, gastrolavage, application of carbon through a nasogastric tube, intubation and controlled ventilation in case of coma and continuous stand by for defibrillation. Additionally patients with stable parameters should be monitored in intensive care units because often there are no precursors of cardiac or pulmonary complications. We report the case of a 49-year old women with ingestion of 2500 mg of amitriptyline who suffered from multiple cardiac arrhythmias with following cardiac arrests and who required multiple defibrillations and resuscitation.

Brugada syndrome following tricyclic antidepressant overdose

The Brugada syndrome, a pro-arrhythmogenic repolarization abnormality, is becoming increasingly recognised as a cause of collapse and sudden cardiac death. We report a case of a 48-year-old man with a tricyclic overdose and a delayed presentation of the Brugada pattern in the ICU. This case raises the need for clinicians to be aware of the Brugada pattern and those patients potentially at risk.

An autopsy case of imipramine poisoning

We present a fatal imipramine poisoning. Quantitative analysis of imipramine and its metabolite, desipramine, was performed by high-performance liquid chromatography. The concentrations of imipramine and desipramine were 18.67 microg/mL and 6.21 microg/mL in heart blood and 6.90 microg/mL and 1.77 microg/mL in the femoral venous blood, respectively. We concluded that the cause of death was due to imipramine poisoning.

Child and adolescent suicides in Virginia: 1987 to 2003

OBJECTIVES

The aim of this study was to better understand suicides in children and adolescents using records from the Office of the Medical Examiner of Virginia from 1987 to 2003.

MAIN FINDINGS, KEY DATA, AND STATISTICS

Suicide accounted for 16.8% of unnatural deaths. Suicide rates were highest for Caucasians. Guns were the most common method of death for suicides, followed by hanging and poisoning. Poisoning other than carbon monoxide accounted for 7.8% of suicides, with tricyclic antidepressants (TCAs) the most identifiable poison. Female youths were 10 times more likely to die from TCAs than male youths, after adjusting for race and age.

CONCLUSIONS

Guns and hanging were the principal methods of suicide. Among the antidepressants, TCAs have been the most common poisons used in suicide. Increasing age was a powerful determinant of suicide. Some patients may have stockpiled their TCAs for a while before their TCA overdose. Other suicide victims may have used TCA supplies from family members. Hence, some of the suicide victims may not have taken TCAs on a regular basis before committing suicide. Further exploration of TCA-induced suicidal thoughts is needed. Conclusions cannot be made at the time about the precise role that TCAs played in TCA-induced suicide reported in our study.

Tissue distribution of mirtazapine and desmethylmirtazapine in a case of mirtazapine poisoning

An ingestion of an unknown quantity of mirtazapine in a suicide attempt leading to death is described. Sertraline and amitriptyline have been co-ingested. Because mirtazapine is reported to be relatively safe in overdose, body fluids and tissues were investigated for both mirtazapine and desmethylmirtazapine by high-pressure liquid chromatography/tandem mass spectrometry following liquid-liquid extraction. The limit of detection was sufficiently low to also apply the assay in pharmacokinetic studies. The levels of amitriptyline and nortriptyline were very low (38 and 19 ng/mL femoral venous blood) and the amount of sertraline in blood taken from the femoral vein (880 ng/mL) was considerably lower than those seen in overdosage. Accumulation of mirtazapine and N-desmethylmirtazapine was evident in fluids and tissues involved in enterohepatic circulation and excretion. The concentration determined in a brain sample suggests a contribution of the metabolite to the drug's pharmacodynamic activity. Based on literature data, significant adverse or synergistic effects among the drugs detected as well as adverse reactions such as a serotonin reaction appeared less probable. Mirtazapine exhibits alpha(1)-antagonistic properties on the cardiac-vascular system and may cause hyponatraemia. In the face of the cardiac findings at autopsy and the lack of an apparent cause of death, these effects of mirtazapine may have initiated a process leading to death.

CYP2D6 and CYP2C19 genotypes and amitriptyline metabolite ratios in a series of medicolegal autopsies

In a series of 202 postmortem toxicology cases, the CYP2D6 and CYP2C19 genes were genotyped, and the concentrations of amitriptyline (AT) and six metabolites were analyzed. The polymorphic CYP2D6 and CYP2C19 genes encode enzymes participating in the metabolism of several potentially toxic drugs, and mutations in these genes may lead to adverse drug reactions, possibly even intoxications. AT was chosen as the substrate of interest because it is mainly metabolized by these enzymes, is considered relatively toxic, and ranks among the major causes of fatal drug poisoning in Finland. Our objective was to evaluate genetically determined interindividual variation in conjunction with metabolite ratios of drugs found in toxicological analysis in a series of medicolegal autopsies. Positive correlations were found between the proportion of trans-hydroxylated metabolites and the number of functional copies of CYP2D6 and between the proportion of demethylated metabolites and the number of functional copies of CYP2C19. None of the accidental or undetermined AT poisonings coincided with the CYP2D6 or CYP2C19 genotype which predicts a poor metabolizer phenotype. However, an unusually high femoral blood concentration of AT, 60mg/l, was found in one suicide case with no functional CYP2D6 genes. Our study shows a concordance of AT metabolite patterns with CYP2D6 and CYP2C19 genotypes in the presence of confounding factors typical for postmortem material. This result demonstrates the feasibility of postmortem pharmacogenetic analysis and supports the dominant role of genes in drug metabolism.

Acute poisoning: understanding 90% of cases in a nutshell

The acutely poisoned patient remains a common problem facing doctors working in acute medicine in the United Kingdom and worldwide. This review examines the initial management of the acutely poisoned patient. Aspects of general management are reviewed including immediate interventions, investigations, gastrointestinal decontamination techniques, use of antidotes, methods to increase poison elimination, and psychological assessment. More common and serious poisonings caused by paracetamol, salicylates, opioids, tricyclic antidepressants, selective serotonin reuptake inhibitors, benzodiazepines, non-steroidal anti-inflammatory drugs, and cocaine are discussed in detail. Specific aspects of common paediatric poisonings are reviewed.

[Cardiac arrhythmia in amitriptyline poisoning in children]

Amitriptyline (Antideprin) determines severe intoxications, especially because of its cardiac side effects.

METHOD

We studied 8 children (2-14 years old) admitted with signs of amitriptyline intoxication.

RESULTS

The clinical picture revealed altered general status, generalized hypertonia, arterial hypotension up to collapse, mydriasis, coma and cardiac arrhythmia. ECG monitoring showed ventricular premature beats, isolated, couplets and triplets, ventricular tachycardia and torsade des points, severe ventricular repolarisation disturbances with diffuse subendocardial ischemia. The treatment consisted in: gastric lavage with activated charcoal, alkalinisation with sodium bicarbonate, antiarrhythmic drugs and sustained vital functions. All cases recovered in 4-6 days.

CONCLUSION

The severity of amitriptyline intoxication requires continue clinical and ECG monitoring, for early detection of some life threatening cardiovascular events. Thus, the treatment will be started early and will alleviate the severe prognosis of this intoxication.

Medical management of deliberate drug overdose: a neglected area for suicide prevention?

OBJECTIVES

Overdoses account for a quarter of all suicides in England. The number of people who survive the immediate effects of their overdose long enough to reach medical attention, but who subsequently die in hospital is unknown. The aim of this study was to determine the proportion of overdose suicides dying in hospital and describe their sociodemographic characteristics.

METHOD

Cross sectional analysis of routinely collected Hospital Episode Statistics data for England (1997 to 1999) to identify hospital admissions for overdose among people aged 12+ and the outcome of these admissions.

RESULTS

Between 1997 and 1999 there were 233 756 hospital admissions for overdose, 1149 (0.5%) of these ended in the death of the patient such deaths accounted for 28% [corrected] of all overdose suicides and 8% [corrected] of total suicides. The median time between admission and death was three days (interquartile range one to nine days). The most commonly identified drugs taken in fatal overdose were paracetamol compounds, benzodiazepines, and tricyclic/tetracyclic antidepressants.

CONCLUSION

Around a quarter of all overdose suicide deaths occur subsequent to hospital admission. Further more detailed research is required to discover if better pre-admission and in-hospital medical management of those taking serious overdoses may prevent some of these deaths.

Are one or two dangerous? Tricyclic antidepressant exposure in toddlers

Tricyclic antidepressants (TCA), increasingly prescribed for multiple indications in children and adults, are responsible for many pediatric poisonings. Though the majority of TCA exposures in this age group remain asymptomatic, several reports in the English language literature reveal significant morbidity as well as fatalities in toddlers, primarily from imipramine and desipramine. These few cases indicate that doses of 10-20 mg/kg (one to two pills) have the potential for toxicity and fatalities. More recent studies have focused on the relative safety of small exposures suggesting that with doses less than 5 mg/kg the patient may be safely observed at home. Though further studies are necessary to determine the exact dosing that places the child at risk, the authors recommend a 6-h Emergency Department observation period for children who ingest more than 5 mg/kg of most TCAs, as clinical toxicity becomes evident within this time frame.

Excess fatality from desipramine and dosage recommendations

Higher case fatality rates (CFR) were previously reported from desipramine than for 3 other tricyclic antidepressants (TCAs): amitriptyline, nortriptyline, and imipramine. The database of the American Association of Poison Control Centers (AAPCC) Toxic Exposure Surveillance System (TESS) for the 20 years 1983-2002 was used to evaluate the CFR of desipramine and the other TCAs. The CFR of desipramine was 2.25-, 2.31-, and 2.62-fold the CFR for amitriptyline, nortriptyline, and imipramine, respectively (P < 0.001). Mechanisms of desipramine toxicity and its dosage recommendations are discussed. Desipramine and nortriptyline have higher distribution volumes and erythrocyte/plasma ratios than their parent compounds imipramine and amitriptyline. This implies lower therapeutic plasma levels and reduced doses for desipramine and nortriptyline compared with their parent compounds. Such adjustments have been done for nortriptyline, but not for desipramine. The authors suggest that the high CFR of desipramine might be reduced by lowering its dose, therapeutic plasma level, and maximal pill content.

The Management of Tricyclic Antidepressant Poisoning

Although there have been descriptive, uncontrolled clinical reports of removal of tablet debris by gastric lavage, there have been no clinical studies that have demonstrated that this has any impact on outcome in patients with tricyclic antidepressant (TCA) poisoning. There is also the possibility that lavage may increase drug absorption by pushing tablets into the small intestine. Furthermore, gastric lavage in patients with TCA poisoning may induce hypoxia and a tachycardia potentially increasing the risk of severe complications such as arrhythmias and convulsions. In view of the paucity of evidence that gastric lavage removes a significant amount of drug and the risk of complications associated with the procedure, the routine use of gastric lavage in the management of patients with TCA poisoning is not appropriate. Volunteer studies have shown generally that activated charcoal is more likely to reduce drug absorption if it is administered within 1 hour of drug ingestion. In the one volunteer study that looked at later administration of activated charcoal, there was a 37% decrease in plasma concentration associated with administration of activated charcoal at 2 hours post-ingestion. There have been no clinical studies that enable an estimate of the effect of activated charcoal administration on outcome in the management of patients with TCA poisoning. Volunteer studies have shown that multiple-dose activated charcoal increases the elimination of therapeutic doses of amitriptyline and nortriptyline, but not of doxepin or imipramine; however, these studies cannot be directly extrapolated to the management of patients with TCA poisoning. There have been no well designed controlled studies that have assessed the impact of multiple-dose activated charcoal in the management of patients with TCA poisoning. Because of the large volume of distribution of TCAs, it would not be expected that their elimination would be significantly increased by multiple-dose activated charcoal.Haemoperfusion, haemodialysis and the combination of these procedures do not result in significant removal of TCAs and are not recommended in the management of patients with TCA poisoning.

Hemoperfusion in a child with amitriptyline intoxication

Tricyclic antidepressant overdose is one of the most common causes of serious drug poisoning in children and adults. We report a 17-month-old girl with severe amitriptyline intoxication. She was admitted to hospital because of lethargy and seizures. It was estimated that she took approximately 75 mg/kg of amitriptyline 2 h before admission. On examination she was comatose, had ventricular tachycardia and multifocal clonic seizures. Intravenous fluid, per oral activated charcoal, diazepam, lidocaine, and sodium bicarbonate infusion were given. However, there was no response to this therapy, and the patient remained in a deep coma with cardiac arrhythmias and seizures. Hemoperfusion (HP) was performed for 2 h. During this procedure, cardioversion was used six times due to ventricular fibrillation. She had a very good clinical response to HP and no complication was observed. We suggest that HP may be an effective treatment in children with severe amitriptyline intoxication.

Tricyclic Antidepressant Poisoning

All tricyclic drugs are potentially able to cause the main acute CNS toxic syndromes of coma and convulsions. Dosulepin (dothiepin) seems more likely to cause convulsions than other drugs in this class, and amitriptyline also appears a more toxic tricyclic agent. Coma is the most useful sign indicative of toxic risk and appears to predict severe toxic complications (fits and arrhythmias) more reliably than ECG changes. Prophylactic therapy against convulsions has not been shown to be effective. Use of an anticholinesterase (physostigmine) is not recommended for management of coma. There is no good evidence base to support a particular anticonvulsant.

Positive determinations of tricyclic antidepressant drugs in the material of toxicological laboratory--analysis of trends

This paper presents the analysis of trends in a number of cases and an average age of patients for whom determination of tricyclic antidepressants (TCA) showed positive results. The studied data were gathered in toxicological laboratory of Dept. of Analytical Toxicology and Therapeutic Drug, CM UJ in Kraków. The data were collected in period December 2001 August 2004. The main findings of this study are: The number of cases is exponentially increasing at the rate of 0.068% per day (p = 0.0165). No statistically significant correlation between the number of cases and: (a) day-length (p = 0.9819), (b) day-length change (p = 0.2312), (c) direction of change of day-length (p = 0.4640), d) day of the week (p = 0.7588) has been found, so periodicity of this phenomenon is questionable. It has been observed that the average age of patients is decreasing and the estimated rate of this decrease equals 0.0092-years per day (p = 0.0555). TCA positive patients treated in the Clinic on different days of the week differ in average age (p = 0.0016). From Tuesday till Friday the average age of patients is increasing. In the middle of the studied period the increase started from 30-year-olds on Mondays and ended with 48-year-old patients on Friday. At weekends the average dropped to 38 and stayed constant. On Mondays the average was about 46.

B-type natriuretic peptide plasma concentration in acutely poisoned patients

B-type natriuretic peptide (BNP) is synthesized in the cardiac ventricles upon ventricular myocyte stretch. BNP plasma concentration is useful in cardiology especially for identifying patients with congestive heart failure (CHF), as a prognostic marker of acute coronary syndromes and independent predictor of sudden cardiac death. Its value in clinical toxicology is unclear. As toxins frequently produce deleterious effects on the cardiovascular system we have decided to carry out the pilot study on BNP plasma levels in acutely poisoned patients. The 117 patients (65 males and 52 females) treated at the Department of Clinical Toxicology Jagiellonian University Medical College in Kraków in 2004 were included. 42 of them were intoxicated with ethanol, 35 with pharmaceuticals (mostly tricyclic antidepressants), 13 with CO. The mean age of examined group was 34.07 +/- 12.08 year. The control group consisted of 54 healthy volunteers and employees of the Department (mean age; 32.7 +/- 11.74). A significantly higher BNP concentration was found in poisoned patients than in the control group. The highest BNP plasma concentration was noted in pharmaceutical poisoned patients. Mean BNP concentration in poisonings of minor severity (grade 1) was significantly lower then in moderate (grade 2) or severe (grade 3) poisonings. BNP plasma measurement as an additional marker of cardiac disturbances in clinical toxicology practice may be suggested.

Management of the Cardiovascular Complications of Tricyclic Antidepressant Poisoning

Experimental studies suggest that both alkalinisation and sodium loading are effective in reducing cardiotoxicity independently. Species and experimental differences may explain why sodium bicarbonate appears to work by sodium loading in some studies and by a pH change in others. In the only case series, the administration of intravenous sodium bicarbonate to achieve a systemic pH of 7.5-7.55 reduced QRS prolongation, reversed hypotension (although colloid was also given) and improved mental status in patients with moderate to severe tricyclic antidepressant poisoning. This clinical study supports the use of sodium bicarbonate in the management of the cardiovascular complications of tricyclic antidepressant poisoning. However, the clinical indications and dosing recommendations remain to be clarified. Hypotension should be managed initially by administration of colloid or crystalloid solutions, guided by central venous pressure monitoring. Based on experimental and clinical studies, sodium bicarbonate should then be administered. If hypotension persists despite adequate filling pressure and sodium bicarbonate administration, inotropic support should be initiated. In a non-randomised controlled trial in rats, epinephrine resulted in a higher survival rate and was superior to norepinephrine both when the drugs were used alone or when epinephrine was used in combination with sodium bicarbonate. Sodium bicarbonate alone resulted in a modest increase in survival rate but this increased markedly when sodium bicarbonate was used with epinephrine or norepinephrine. Clinical studies suggest benefit from norepinephrine and dopamine; in an uncontrolled study the former appeared more effective. Glucagon has also been of benefit. Experimental studies suggest extracorporeal circulation membrane oxygenation is also of potential value. The immediate treatment of arrhythmias involves correcting hypoxia, electrolyte abnormalities, hypotension and acidosis. Administration of sodium bicarbonate may resolve arrhythmias even in the absence of acidosis and, only if this therapy fails, should conventional antiarrhythmic drugs be used. The class 1b agent phenytoin may reverse conduction defects and may be used for resistant ventricular tachycardia. There is also limited evidence for benefit from magnesium infusion. However, class 1a and 1c antiarrhythmic drugs should be avoided since they worsen sodium channel blockade, further slow conduction velocity and depress contractility. Class II agents (beta-blockers) may also precipitate hypotension and cardiac arrest.

Amiodarone fails to improve survival in amitriptyline-poisoned mice

OBJECTIVE

Amiodarone, a class III antidysrhythmic agent, blocks Na+, Ca2+, and K+ channels as well as the beta-adrenergic receptor. Despite increased use of amiodarone for wide-complex tachycardia, its efficacy in the treatment of dysrhythmias induced by tricyclic antidepressants has not been tested. We investigated the effect of amiodarone and amitriptyline in a mouse lethality model.

METHODS

The LD50 of amitriptyline obtained from reference sources was confirmed by giving 100 mg/kg to 40 mice by intraperitoneal (IP) injection. The safety of the treatment dose of amiodarone was confirmed by giving 50 mg/kg by IP injection to 10 mice. One hundred and nine mice were randomized to receive pretreatment with 50 mg/kg amiodarone (n=55) or an equal volume of saline or water as a volume control (n=54). Thirty minutes after pretreatment or control injection, the mice received amitriptyline, 100 mg/kg. Outcome was defined as death or survival 3 h after amitriptyline injection.

RESULTS

In our confirmation of the LD50 of amitriptyline, 25/40 mice died (62.5%). None of the 10 mice that received only amiodarone died. In the control + amitriptyline arm, 36/54 (66.7%) died, compared with 39/55 (70.9%) in the amiodarone+amitriptyline arm (X2, p=0.663). Power analysis demonstrated a 90% chance of finding a 28% difference.

CONCLUSIONS

Pretreatment with amiodarone does not appear to significantly alter the lethality of amitriptyline poisoning in mice. Given the inability to monitor cardiac activity in this model, further investigation in a larger animal is required.

Recreational amitriptyline abuse

Amitriptyline is a potent anticholinergics, rarely used as a drug of abuse. Two cases of amitriptyline dependency lasting for almost twelve months were described. According to the patients the abuse with amitriptyline guarantee them safety not to be uncovered by parents and doctors who systematically checked their urine with typical narcotic tests.

CASE REPORT

Two patients with a history of abuse with amphetamine and clonazepam were admitted to the Clinic because of intoxication with amitriptyline. They denied the suicidal attempt and explained that they used amitriptyline in a dosage of 100 to 200 mg per day as a drug of abuse. On the day of admission one of the patients had increased the dosage up to 600 mg which caused an acute intoxication.

CONCLUSION

Antidepressants should be treated as a drugs with possible abuse ability.

Association between mortality from suicide in England and antidepressant prescribing: an ecological study

BACKGROUND

Antidepressant prescribing has been increasing in England. Studies in other countries suggest that while this may be associated with reduced suicide rates, it may also be associated with increased fatal poisoning from antidepressant drugs. We therefore conducted an ecological study to assess the association between prescription rates for antidepressants and suicide or fatal antidepressant-related poisoning in England.

METHODS

The Office for National Statistics provided information on the number of suicides, antidepressant-related poisoning deaths and populations for England between 1993 and 2002. The Department of Health supplied data on prescriptions for all antidepressants dispensed in England. Associations between prescriptions and deaths were assessed using Spearman's rank correlation coefficient.

RESULTS

There were 46,747 suicides, 3,987 deaths involving tricyclic antidepressants and 430 involving selective serotonin re-uptake inhibitors and other antidepressants. Increased antidepressant prescribing was statistically associated with a fall in suicide rates (Spearman's rs = -0.73, p = 0.02) and fatal poisoning involving tricyclic antidepressants (rs = -0.64, p = 0.05). In contrast, increased prescribing of selective serotonin re-uptake inhibitors and other antidepressants was statistically associated with an increase in fatal poisoning involving these drugs (rs = 0.99, p < 0.001).

CONCLUSION

Increased prescribing of antidepressants may indicate improved diagnosis and treatment of depression in primary care. Our analysis suggests that this was accompanied by lower suicide rates. A decrease in poisoning deaths involving tricyclic antidepressants may suggest a change in preference for using serotonin reuptake inhibitors and other antidepressant drugs for high-risk patients. This may also partially explain the increase in deaths involving these drugs. Due to the ecological nature of the design, we cannot say conclusively whether reduced suicide rates are a direct consequence of increased antidepressant prescribing rates. To confirm these associations, individual level data on prescribing and suicide is needed.

Deadly pediatric poisons: nine common agents that kill at low doses

More than 97% of pediatric exposures reported to the AAPCC in 2001 had either no effect or mild clinical effects. Despite the large number of exposures, only 26 of the 1074 reported fatalities occurred in children younger than age 6. These findings reflect the fact that, in contrast to adolescent or adult ingestions, pediatric ingestions are unintentional events secondary to development of exploration behaviors and the tendency to place objects in the mouth. Ingested substances typically are nontoxic or ingested in such small quantities that toxicity would not be expected. As a result, it commonly is believed that ingestion of one or two tablets by a toddler is a benign act and not expected to produce any consequential toxicity. Select agents have the potential to produce profound toxicity and death, however, despite the ingestion of only one or two tablets or sips. Although proven antidotes are a valuable resource, their value is diminished if risk after ingestion is not adequately appreciated and assessed. Future research into low-dose, high-risk exposures should be directed toward further clarification of risk, improvements in overall management strategies,and, perhaps most importantly, prevention of toxic exposure through parental education and appropriate safety legislation.

Prolonged gastric emptying half-time and gastric hypomotility after drug overdose

A prospective study was undertaken to determine if gastric motility and emptying are altered by the ingestion of overdoses of tricyclic antidepressants, acetaminophen, opioid-acetaminophen mixtures, carbamazepine or phenytoin. Gastric scintigraphy was used to measure gastric emptying half-time and assess gastric motility in 104 patients at initial presentation and again at follow-up (n = 85). Patients were imaged for 5 hours after being given 20 MBq of 99mTc tin colloid to drink. Drug serum levels were measured on all patients at initial presentation and at follow-up. We observed markedly prolonged gastric emptying half-times and severe hypomotility at initial presentation compared with follow-up in the vast majority of patients, except for a small group of patients with phenytoin poisoning. Twelve patients had gastric emptying half-times of over 300 minutes, a further 14 had half-times of over 200 minutes and 21 others had half-times of over 120 minutes. Poisoning is associated with hypomotility and a marked delay in gastric emptying that could influence the clinical course and patient management. These abnormalities may not be due to a direct effect of the ingested drug and factors such as stress may play a role.